Light Speed Barrier

And then there is this "Nothing may travel faster than the speed of light" nonsense.

The theory of relativity is basically good science, it applies the concept of light as a medium to measure the world by.

When you work the math for an object traveling faster than the speed of light, you end up with a square root of a negative number as part of the solution. This only tells me that you cannot see an object that is coming at you faster than the speed of light.

Seems pretty logical.

So, on to the example.

You are on a meteorite that is traveling relative to a point in space at .75C (a plausible rate of travel, per Einstein). There is another meteorite heading straight at that same point in space with the same.75C. Now, you, standing on the first meteor, look up towards the meteor. Relative to your position, how fast is the other meteorite?

Reality: .75 + .75 is 1.50, in other words, half again faster than the speed of light. Work the Einsteinian math, and you end up with a square root of a negative number.

Curiously, electrical engineers use these "impossible" numbers daily.

This is a quote from a lecture, swiped from some university:
   "There's the problem that an object going faster than light would have a length that is an imaginary number - the square root of a negative number - and this doesn't seem to make any sense"

As often quoted, common sense isn't.

Check out Use of imaginary numbers for the short answer, or for more in depth, check the wiki Complex_number entry.

Seems like a lot of practical math and science for something derided as imaginary.

Sam C says


I would invite you to actually read Einsteins theory of relativity before making such remarks. Nothing can appear to travel at the speed of light because as an object accelerates towards 3 x 108ms-1 the length of that object tends to zero. Which is why we are unable to observe photons. As well as this, nothing with mass can travel at, or higher than the speed of light. An objects mass becomes infinitely great as it undergoes acceleration, meaning an infinite amount of energy is needed to propel the object to the speed of light, which is impossible.

Thank you for your comment. More information about relativity can be found here: Special Relativity for the wiki version, or Special and General Principle of Relativity for the original text.

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